Sinker control means and method for circular knitting machine



March 9, 1965 F. s, ANTHONY ETAL 3,172,274

SINKER CONTROL MEANS AND METHOD F'OR CIRCULAR KNITTING MACHINE 6 Sheets-Sheet l V25 i053 BY 2O ngamm-LW.

A TTORNE KS March 9, 1965 F. s. ANTHONY ETAL 3,172,274

SINKER CONTROL MEANS AND METHOD FOR CIRCULAR KNITTING MACHINE Filed Sept. 28, 1962 6 Sheets-Sheet 2 March 9, 1965 F. s. ANTHONY ETAL 3,172,274

SINKER CONTROL MEANS AND METHOD FOR CIRCULAR KNITTING MACHINE Filed Sept. 28, 1962 6 Sheets-Sheet 3 March 9, 1965 F. s. ANTHONY ETAL 3,172,274

SINKER CONTROL MEANS AND METHOD FOR CIRCULAR KNITTING MACHINE 6 Sheets-Sheet 4 Filed Sept. 28, 1962 VENTORSI Pomar-:5T S. ANWI'IYAONY mi WHJAYM ROY COLQLMTV mxmumw ATTORNEYS SINKER CONTROL MEANS AND METHOD FOR CIRCULAR KNITTING MACHINE 6 Sheets-Sheet 5 Filed Sept. 28, 1962 lll March 9, 1965 F. s. ANTHONY ETAL 3,172,274

SINKER CONTROL MEANS AND METHOD FOR CIRCULAR KNITTING MACHINE 6 Sheets-Sheet 6 Filed Sept. 28, 1962 United States Patent O 3,172,274 SINKER CQNI'RGL MEANS AND METHOD FR CERCULAR KNlTTlNG MACHENE Forrest S. Anthony and William Roy Colqnitt, Shelby, N., assignors to Hudson Hosiery Company, Charlotte, PLC., a corporation of North Carolina Filed Sept. 2S, i952, Ser. No. 226,892 8 Claims. (Cl. ooti) This invention relates to an improved means and method for controlling the sinkers of a single-feed circular hosiery machine of the type which is adapted to knit sheer seamless non-run ladies hosiery in which the leg and foot portions are formed of alternate single courses of small plain stitch loops in every Wale and intervening courses of a recurring pattern of large plain and tuck stitches.

It has been found that this type of so-called non-run hosiery can be made more run-resistant by making the plain stitch loops of the alternate courses approximately half as large as the stitch loops of the intervening courses having both plain and tuck stitches therein. It is well known -to knit this type of hosiery on a two-feed circular hosiery knitting machine by forming the alternate courses of small plain stitches at one knitting station While forming the recurring pattern of large plain and tuck stitches in the intervening courses at the other knitting station. While this type of hosiery can be economically formed on a two-feed circular hosiery knitting machine, there are many single-feed circular hosiery knitting machines presently producing plain sheer seamless ladies hosiery and the only known method of kitting this type of hosiery on a single-feed machine requires extensive modification of the machine and the point at which the stitch length is changed from course to course can not be accurately controlled to confine the same to a single Wale. The coniining of the stitch length change to a single Wale is desired to avoid objectional streaks that would otherwise occur as when the change takes place in a gradual manner over a group of adjacent wales. As is well known to those skilled in the art, this problem is not present in a two-feed machine because both yarns are knitting at the same time and therefore no stitch length change is required from one course to the next.

With the foregoing in mind, it is a primary object of the present invention to provide an improved method and means for knitting sheer non-run hosiery which can be easily applied to existing single-feed hosiery knitting machines and which insures that the changing of the stitch length, to form alternate courses of small stitch loops and intervening courses of large stitch loops, always occurs in the same needle Wale throughout the knitting of the leg and foot.

it is another object of the present invention to provide an improved method and means for knitting hosiery of the type described which includes improved sinker control means for a single-feed knitting machine of the type having radially extending sinkers supported for movement between the circularly arranged needles and having nebs thereon with a rst stitch drawing ledge of a certain height in front of the neb and a second higher stitch drawing ledge behind the neb, said sinker control means including cam means operable on the sinkers during each rotation of the needle cylinder to alternately position the sinkers where the needles will form small stitch loops over the tirst stitch drawing ledge in front of the neb during one rotation of the needle cylinder and to then position the sinkers where the needles will form large stitch loops over the second higher stitch drawing ledge behind the neb during the next rotation of the needle cylinder to thereby form the leg and foot portions of the hosiery of alternate single courses of small stitches and intervening single courses of large stitches.

3,172,274 Patented Mar. 9, 1965 It is a further object of the present invention to provide an improved sinker control means of the type described for changing the radial position of the sinkers following the knitting of each course, .the sinker control means including a first movable sinker control cam engageable only with sinkers having high butts and a second movable sinker control cam engageable with sinkers having low butts, the sinkers having high butts being notched at their outer and lower portions so that said second movable sinker control cam is engageable only with the sinkers having low butts and the operation of the sinker control cams being timed with rotation of the needle cylinder, so as -to insure that the ends of all small stitch loop plain courses and the ends of all intervening courses of large plain and tuck stitches will occur at the same needle Wale in both the leg and foot portions of the hose.

It is yet another object of the present invention to provide an improved method of knitting a non-run sheer ladies hose of the type described on a circular single-feed knitting machine of the type described which includes knitting the leg while varying the radial position of the sinkers with each rotation of the needle cylinder to form small stitch loops over the ledges in front of the nebs during alternate single rotations and to form large stitch loops over the ledges behind the nebs during intervening single rotations, then shogging the needle cylinder onehalf revolution, and knitting the foot while continuing to vary the radial position of the sinkers with each rotation of the needle cylinder, the changing of the radial positions of .the sinkers occurring at the same Wale in both the leg and foot portions of the hose.

Some of the objects ofthe invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which- FIGURE 1 is a side elevation of the upper left-hand portion of a circular knitting machine and showing the present sinker control means attached thereto;`

FIGURE 2 is an elevation of the rear of the knitting machine with the sinker control means attached thereto and showing the upper portion of the needle cylinder and the sinker cap shifted to the lett of its normal position;

FIGURE 3 is a side elevation of the right-hand side oi the machine and illustrating the arrangement of the pattern drums which control the operation of the sinker control means;

FIGURE 4 is a vertical sectional view through the secondary sinker control drum, showing the primary sinker control drum in elevation, and being taken substantially along the line 4 4 in FIGURE 2;

FIGURE 5 is a vertical sectional View through the primary sinker control drum, taken substantially along the line 5 5 in FIGURE 2;

FIGURE 6 is a view similar to FIGURE 5, but showing the next control lever on primary sinker control drum;

FIGURE 7 is a View similar to FIGURES 5 and 6, but showing the next control lever on the primary sinker control drum;

FIGURE 8 is a plan view of the sinker cap, with a portion of the upper plate broken away at the knitting station to illustrate the position of the sinker control cams and the movement of the sinkers with the sinker control cams in outermost position;

"ice

FIGURE 9 is a fragmentary View similar to the central portion of FIGURE 8, but showing the upper sinker control cam in an innermost or operative position;

FIGURE 10 is a view similar to FIGURE 9, but showing both the upper and lower sinker control cams in an innermost or operative position;

FIGURE 1l is an elevation looking inwardly at the side of the sinker cap and in the direction indicated by line lil-11 in FIGURE 8;

FIGURE 14 is a view similar to FIGURES 12 and 13, Y

but showing both the upper and lower sinker control cams in an innermost or operative position with a low butt sinker beingimoved inwardlyso that the needles draw the yarn down to form large stitch loops over the stitch founing ledge behind the nebs.

The sinker controll means of the present invention is shown associated with a single-feed circular hosiery knitting machine of the type known as a Bentley Model KL, manufactured by the BentleyV Engineering Company, Limited, of Leicester, England. However, it is to be understood that the present invention may also be used with other typesof single-feed circular hosiery knitting machines'and its use is not to be limited to the particular machine shown. Only those conventional portions of the knitting machine which are necessary -to an understanding of the present invention have been shown in the drawings.

Referring particularly topFIGURES l-3, the machine includes the usual frame which ris normally supported on legs, not shown. A lower bed plate 21 is supported at one side of Vthe frame 20 and at its other side on the upper end of a support bracket 20a (FIGURE l). The

lower bed plate' 21 rotatably supports the usual needle cylinder bevel gear, not shown, and which is driven through the usual drive means, including a mainrdrive shaft 22 having a bevel gear 23 at yone endV (FIGURE l). The opposite end of main drive shaft 2T. isV provided with the usual driving pulleys 24 which are normally engaged by a shiftable drive belt, not shown, to selectively rotate or reciprocate the needle cylinder 25. The drive mechanism of the knitting machine also includes a high speed gear 26 which is xed on one end of a short shaft 27 (FIGURE 3) that is ro-tatably'supported in the frame 2i) and has the conventional bull gear, not shown, xed on its inner end.

A main pattern shaft 3i) is supported for rotationY in the frame 20 (FIGURE 3)v and supports the usual patternV chain sprocket, clutch shifting drum, and a driving gear, not shown, which engages with an intermediate drive gear 31 to impart movement to a gear 32 which is iixed on one end of the main pattern drum 33 (FIGURE 3,). The machine is usually provided witha conventional striper drum 34 (FIGURES l and 2) which is provided with a racking wheel 35 that is in yturn racked in a step-by-step manner by a racking pawl 36; The striper drum 34 is mounted for rotation on a support shaft 37 which is supported at one end in' spaced apart boss members (FIGURE 2) at the lower end Vof a support bracket 40`the upper portion of which is suitably secured to the upper' horizontal portion of therframe 20- (FIGURE 3). The opposite end of the striper drum support shaft 37'is'suitably supported in the medial portion of a supportarm 41 (FIG,- URE 1), the lower end of which is suitably. secured tothe medial portion of the support bracket 26a and the upper end of which supports a shaft 42. The support bracket 20a also supports one end of a thrust rod control shaft 44 and a main pattern drinn support shaft 45 (FIG- URE 1). K

A needle cylinder supportturbe 50 (FIGURE l) extends upwardly into the lower bed plate 21 and normally supports the lower end of the needlecylinder in a conventional manner and the tube 50 may be raised andY lowered to change the length of stitch being formed by the knitting machine in a well-known and conventional manner. An upper bed plate 51 is suitably Supported in spaced relationship above the lower bed plate 21 and the needle cylinder extends upwardly through the upper bed plate and has a sinker head 52 suitably secured thereto in a conventional manner. The sinker head has radially extending slots Itherein which support radially movable sinkers which are divided into a group of short butt sinkers, indicated lbroadly at S in FIGURES 8-10, and a group of long butt sinkers, indicated broadly at S' in FIGURES 8-10. The sinkers cooperate with the needles N (FIG- URES 12-14) to form knit stitch loops Vwhen yarn is fed to the needles and the needles are lowered by the usual stitch cams,-not shown. The stitch cams are supported in the usual manner on the upper bed plate 51 and adjacent the needle cylinder 25.

The sinker head 52 is xed to and rotates with the needle cylinder 25 and'is provided with a sinker cap 55 (FIGURES l and 8) which is provided with outwardly extending lugs having stop screws 55a and 55b threadably embedded therein. The adjustment screws 55a and 55b are provided to adjust the amount of relative movement of the sinker cap 55' with reciprocation of the needle cylinder 25 as their inner ends alternately engage the opposite sides of a bunter post 56. The lower end of' the bunterpost 56 is suitably secured to the upper bed plate 51 (FIGURE l) and supportsthe usual widening pick 57 in a conventional manner. The sinker cap 55 contains suitable cams which act upon the butts of the sinkers to control their radial position, relative to the circle of needles N supported -in the needle cylinder 25.

The rear end of a latch ring 60' (FIGURES l and 3) is pivotally supported as atV 6l in theupper end of a support post 62, the lower end of which is suitably supported on the upper bed' plate 5l in a conventional manner. The forward end of the latch ring 60 is suitably supported on the upper end of the bunter post 56 and supports the usual yarn feed iingers 6G11 for movement into and out of yarn feeding position at the knitting station. Movement of the yarn feeding ngers 62 is controlled in a conventional manner by thrust rods 63 (FIGURE l) which extend downwardly thererom'through the upper andl lower bed plates 51 and 2l and are controlled by suitable cams, not showmon the main pattern drum 33. The latch ring 63 also `supports the usual dial drive mechanism, broadly indicated at 65 in FIGURES 1 and 3, and the dial, not shown, which is provided with the usual transfer points that are used in the formation of a turned welt at the top of the hose.

The parts heretofore described are conventional parts of a single-feed circular hosiery knitting machine and are shown to aid in understanding the present invention which will now be described. While some of the parts to be described have been used heretofore for other purposes, they are used in a novel manner in connection with the present invention.

As has heretofore been mentioned, the present invention' is of particular value when knitting a seamless nonrun sheer ladies hose in which the leg and foot portions are formed by knitting` plain stitch loops on all of the needles in alternate single courses, and knitting a recurring pattern of plain and tuck stitches in intervening single courses, Also, in order to increase the run-resistant quality' of the fabric, the courses which contain the plain' stitch loops in every Wale have shorter or smaller stitch loops than the stitch loops of the courses having the patf tern of plain and tuck stitches.

In the present invention this-variation in stitch length in adjacent courses is accomplished by controlling the position of the sinkers, relative to the needles at the time that the needles are lowered to stitch drawing position. Thus, in accordance with the present invention the sinkers are maintained in a first outermost position during alternate rotations of the needle cylinder so that the needles N form their stitch loops by drawing the yarn down over 5. the low stitch drawing ledges in front of the nebs of the sinkers to form short or small stitch loops. Then the sinkers are maintained in a second innermost position during intervening rotations of the needle cylinder so that the needles N form their tuck and plain stitch loops by drawing the yarn down over the higher stitch drawing ledges behind the nebs of the sinkers to form long or large stitch loops, in a manner to be presently described. In order to accurately determine which needle will start and complete the knitting of the courses of long and short stitch loops pattern controlled movable sinker control cams act on the short or low butt sinkers S and the long or high butt sinkers S in a manner to be presently described.

As shown in FIGURES 12-14, the short butt sinkers S and the long butt sinkers S are each provided with a neb 70, a iirst stitch drawing ledge 71 positioned in front of or inwardly of the neb 70 and a second stitch drawing ledge 72 positioned behind or outwardly of the neb 70. It will be noted that the upper edge of the iirst stitch drawing ledge 71 is below the level of the second stitch drawing ledge 72 so that when the needles N draw the yarn down to stitch drawing level and over the iirst stitch drawing ledge 71, short or small stitch loops are formed by the needles and when the needles N draw the yarn down to stitch drawing level and over the second stitch drawing ledge, they form long or large stitches. As shown in FlGURE i3, each of the long butt sinkers S is cut away, as at 73, at the lower portion of its outer end, for purposes to be later described. Referring particularly to FIGURE 8, it will be noted that the sinker cap 55 includes an insert cam 7S which extends downwardly from the upper lower surface of the sinker cap 55 and limits inward movement of the sinkers Sin the usual manner. At the main knitting station a sinker withdrawing cam 76 is suitably secured to the lower surface of the horizontal portion of the sinker cap 55 and extends between opposite ends of the cam 75. The cam 75 engages the inner portions of the butts of both the long and short butt sinkers to partially withdraw the sinkers as they approach the main knitting station and as the yarn is picked up in the hooks of the raised needles. The outer periphery of the sinker cap 55 is provided with a downwardly extending ilange 77 and an insert cam 7S is fixed against the ilange 77 and extends around the major portion of the sinker cap e'. The insert cam 73 engages the outer portions of the butts of both the long and short butt sinkers to thereby maintain the sinkers in a fixed radial position throughout most of their travel around the sinker cap 55. The insert cam 78 is cut away at the main knitting station so that the sinkers can be moved outwardly by the sinker withdrawing cam 76.

As shown in FIGURES 8, 9, l0 and ll, the flange 77 of the sinker cap 55 is provided with a slot or opening S0 which has three sinker control cams 81, 82 and 83 supported therein. All three of the sinker control cams 81, 82 and S3 are supported at one end on a screw 00a which is threadably supported in the sinker cap 55 and extends through the slot 30. One end of each of the sinker control cams `has an outwardly extending leg which is connected to one end of respective tension springs 842, 85 and 86, the opposite ends of which are connected to a suitable spring perch 87 that is in turn secured to the outer surface of the sinker cap 55. The springs 844-86 normally urge the free ends of the sinker control cams to an outermost position.

The upper control cam S1 and the lower control cam 83 are adapted to be moved inwardly and outwardly between operative and inoperative positions, for purposes to be later described, by pattern control means which will be later described. The center sinker control cam 02 may be termed a fixed cam although its position may be adjusted by an adjustment screw 90 which is threadably supported in a plate member 90a, the lower edge of which is suitably secured to the outer surface of the sinker cap 55 (FIGURE ll). The inner end of the adjustment screw 90 engages the outer surface of a medial portion of the center sinker control cam S2 and the spring S5 resiliently maintains the center sinker control cam 82 in engagement with the inner end of the adjustment screw 90. The screw may be held in adjusted position by any suitable means, such as a lock nut 90b (FIGURE 8) It will be noted that the free end of the sinker control cam 82 has an inwardly beveled cam surface which normally engages the outer portions of the butts of both the short butt sinkers S and the long butt sinkers S to move the sinkers inwardly, relative to the needles, after the needles have been lowered to stitch drawing position. The needles N are lowered to stitch forming level at the point indicated by the section line 12-12 in FIGURE 8 and immediately thereafter the sinkers are moved inwardly of the needle cylinder as the needles are again raised so that the nebs 70 move the shed stitch loops inwardly.

The free ends of the upper sinker control cam S1 and the lower sinker control cam 33 are normally urged to the outermost position shown in FIGURES 8 and 12 by the respective springs 84 and Se. The inner ends of respective control pins 91 and 92 (FIGURE ll) are threadably embedded in outwardly projecting portions of the respective sinker control cams 81, 83. The control pins 91 and 92 are adapted to be engaged by respective control plate members 93 and 94 (FIGURE 1l) which forrn a part of the pattern control means, to be presently described. Inward movement of the respective upper and lower sinker control cams 81 and S3 is controlled by respective pins 95 and 96 (FIGURE 1l) which are suitably secured in the cams S1 and S3 and which are provided with respective adjustment screws 95a and 96a, the inner ends of which are adapted to engage the outer periphery of the sinker cap 55 when the control cams are moved to their innermost position. Suitable lock screws 95b and 96h are provided to hold the respective adjustment screws 95 and 96 in their adjusted position.

The control plates 93 and 94 are suitably secured to the forward or free ends of respective slides or plungers 100 and 101 (FIGURES l and 2) which are supported for sliding movement in a bracket 102 that is in turn supported on the outer end of a stub shaft 103. The inner end of the stub shaft 103 is fixed in a medial portion of the latch ring support post 62 (FIGURE 2). The ends of Bowden wire cables 104 and 105 are connected to pins secured in the sides of the respective plungers 100 and 101 and these Bowden wires 104, 105 at times control operation of the plungers 100, 101 and their respective sinker control plates 81 and 33. The plungers 100 and 101 are normally urged inwardly toward the sinker cap 55 by respective tension springs 106 and 107 (FIGURE 1) which are suitably connected at one end to the respective plungers 100 and 101 and at their other ends to the support bracket 102.

At other times, the plungers 100, 101 may be moved outwardly to an inoperative position by respective lever arms and 111 which are pivotally supported intermediate their ends on the bracket 102 and the lower leg portions of which engage the outwardly extending pins on the sides of the respective plungers 100 and 101. The free ends of the upper legs of the levers 110 and 111 are connected to the ends of respective Bowden wire cables 112 and 113.

The Bowden wires 112 and 113 provide a primary control for the plungers 101 and 100, as well as the sinker control cams S1 and 83 and may be operated to at times inactivate the secondary sinker control means, including the plungers 100, 101 and respective Bowden wires 104, 105, such as during the knitting of the welt, heel and toe of the hose. The lower ends of the housings of Bowden wires 112 and 113 are suitably secured in a shaft 115 (FIGURES 6 and 7). One end of the shaft 115 is supported in a drum support bracket 116, the lower end of which is suitably secured to the frame 20 of the knitting machine. The opposite end of the shaft 115 is Xed in a 7 downwardly depending arm-of an auxiliary support plate 117 (FIGURE 4). y

The lower ends of the Bowden wires 112, 113 are connected to respective levers 120 and 121 which are supported intermediateptheir endson a shaft 122 (FIGURES 6 and`7). One end of the shaft 122 is Xed in thedrurn support'bracket 116 and extends to the left in FIGURE 2 and through'a second drum support bracket 123, the lower end of which is suitably secured to the frame V26 (FIG- URE 3). The` free ends of the respective levers 12%, 121 are adapted to at times engage the outer periphery of an auxiliary pattern drum 125 which is xed on a shaft 126. One end of the shaft 126 (FIGURE 2) is provided with a gear 127 which mates with the gear 32 on the main pattern drum-33m thereby impart rotation to the drum 125'when rotation is imparted to the main pattern drum 33. The shaft`126 is supported for rotation in the drum support brackets 116 and 123.

As shownv in FIGURES 6 and 7, the reading-ends of the levers 120 and 121` are adapted Vto at times engage corresponding camsV 134i, 131,- 132 and 133which arecarried by the auxiliary pattern drum 125 and positioned in alinement with the levers 120l and 121. When the reading ends of the levers 12), 121 vmove onto any of the cams 13G-133, the corresponding Bowden wires 112, 113 will pull onV the respective levers 110, 111 to thereby move both of the plungers 165 and 1411` and their corresponding control plates 93, 94 outwardly. Then, the tension springs 84 and 86 will move the upper sinker cam 81 and the lower singer cam 83 outwardly to the inoperative position shown kin FIGURES 8 and 12. AS

has been stated, the levers 120, 121 and Bowden wiresl 112, 113 are normally used to move the sinker controlV cams 81, 83V to inoperative position and maintain the same in this inoperative position during the knitting of plainknit portions ofthe hose, such as the welt, the heel, and the toe.

In order to alternately move the sinker control cams inwardly and outwardly to operative and inoperative positions in timed relationship to rotation of the needle cylinder, in a manner to be presently'described, the lower ends of the Bowden wires 104, V155 are suitably connected to the outer ends of respective control levers 134, 135 (FIGURES 3 and 4). The medial portions ofthe levers 134, 135 are fxedly connected to medial portions of respective sleeves 136, 137 which are mounted for oscillation and longitudinaly movement on the shaft 122 (FIG- URE 2), for purposes to be later described. The upper or reading ends of the levers 134, 135 at times engage the peripheral surface of respective outwardly extending hub portions140 and 141` on opposite sides of a timing gear 142." The gear 142 is mounted for rotation on one end of a stub shaft 143v which is xe'd in the auxiliary support bracket 117. The teethk of the gear 142 engage the teeth of thel high speed gear 26' (FIGURE 3) to thereby impart continuous-rotation to the gear 142 with .operation of-V the knitting machine.

The hub 140 is provided with a rst set of diametrically opposed'camsr144t, 145 and a second set of diametrically opposed cams 1746, 147 which are otset from the1carnsf144,` 145 (FIGURE 3). The cams 144 and 145- are positioned in one race of the hub 14) and the cams 145 and 147 are positioned in an adjacent race and the reading end of the lever 134 may be switched from one race-to another, in a manner to bel presently described. The hub 141 ofthe gear 142 is also provided with a first set of diametrically opposed cams d, 151 (FIGURE 4) which are positioned in one race of the hub 141 and a second set of diametrically opposed cams 152', 153 which are positioned in an adjacent race. The reading end of the lever 135 may also be switched from one race to the other to engage either theV rst set Vol? earns 15G, 151 or the second set of cams 152, 153, in a manner to be presently described.

A compression spring 155 (FIGURE 2) surrounds the 8 outer end of the shaft 122 andorre end` thereof bears against the outer end of the sleeve 136' of the lever 134 while the opposite end bears against a collar 15e, suitably secured for longitudinal adjustment on the outer end of the shaft 122. Thus, the compression spring 155 normally urges the sleeve portions 135, 137 of the levers 134, 135 to the position shown in FIGURE 2 and against a stop collar 157 so that the reading ends of the respective levers 134, 135 are positioned in alinement to engage the outer periphery of the respective hub portions 14), 141 and the corresponding cams 146, 147' and 152, 153.

The reading ends of the levers 134, 135 are resiliently urged inwardly toward the hubs 140, 141 by respective tension springs 169, 161 which are connected at one end to the free ends of the levers 134, 135 and their opposite ends are connected to a spring perch plate 152 (FIGURE 2). The medial portion of the plate 162 is suitably secured to the outer end ot a support arm 163, the inner end of which is suitably secured to the frame 20 of the knitting machine (FlGURE 3).

When the reading end of the control lever 134, is in engagement with one of the cams on the hub portion 14u of the gear 142, as shown in FIGURE 3, the upper plunger ltilis pulled outwardly so that the free end of the sinker control cam 31 is pulled out to the inoperative position shown in FIGURE 8 by its respective tension spring 34. Then when the reading end of the lever 134 moves oit of the cams on the hub 14?, the Bowden wire 164 is released to thereby allow the tension spring 1% to moveY the plunger 15@ inwardly so that its plate member 93 engages the pin 91 on upper control cam 81 to move the same inwardly to its operative position, as shown in FIGURE 9. The cam lever 135 controls i the operation oi the sinker control cam 81 in a similar o manner and when the reading end of the cam lever engages any of the cams on the hub 141, the plunger 101 is pulled outwardly so that the tension spring will move the lower sinker control cam 83 outwardly to the inoperative position shown in FIGURES 9 and l2. On

the other hand, when the reading end of the lever four complete revolutions for each rotation of the needle cylinder 25 and therefore, the control gear 142 also makes four revolutions for each rotation of the needle cylinder. Thus, with the control levers 134, 135 positioned in alinernent with the respective cams 146, 147 and 152, 153, as shown in FIGURES 2, 3 and 4, during one complete rotation of the needle cylinder, the respective levers 134,

135 wiil be in engagement with the respective cams 145, 152 and therefore the upper and lower sinker control cams 81 and 53 will be maintained in their outermost or inoperative positions, as shownin FIGURES 8 and 12. Then, at the beginning of the next needle cylinder rotation, the lever 134 will move oil of the cam 145 a little before the lever 135 moves olf of the cam 152 so that the upper control cam 31 will move inwardly to operative position a little as shown before the lower sinker control cam S3 moves inwardly-to operative position. The reading ends of both levers 134, 135 will remain olf of the cams and in engagement with the respective hubs 149, 141, so that the upper and lower sinker control cams 51 and 83 will remain in their innermost operative position during this second complete rotation of the needle cylinder. During the third complete rotation of the needle cylinder 25, the levers 134, 135 will be in engagement with the respective cams-147 and 153 and the corresponding sinker control cams 51, 83 will be in inoperative position. During the fourth complete rotation of the needle cylinder 25, the lcvcrs 135 will be in engagement with the respective hubs 14S, 141 and the corresponding sinker control cams 81, 83 will be in operative position. Then the cycle described above will be repeated for each rotation of the gear 142. The exact timing of the inward and outward movement of the upper and lower sinker control cams 31 and 83 during each course will be described in detail in the description of the operation of the machine.

As shown in FIGURES 2 and 5, the medial portion of a lever 170 is supported on the shaft 122 and its reading end is adapted to at times engage the outer periphery of the auxiliary pattern drum 125 and at other times to engage a cam 172 suitably secured thereto (FIGURE 5). The inner end of the lever 170 is connected to one end of a Bowden wire 173, the housing at the opposite end of the Bowden wire 173 being suitably secured in an eX- tension of the auxiliary support plate 117 (FIGURES 2 and 4). The free end of the Bowden wire 173 is suitably connected to an upstanding arm 174, the lower portion of which is suitably connected to the end of the sleeve 137 of the lever 135. When the reading end of the lever 170 moves up onto the cam 172, as during the knitting of the foot portion of the hose, the Bowden wire 173 is pulled to thus shift the sleeves 136, 137 on the shaft 122 and to the left in FIGURE 2, aga-inst the compression spring 155. Shifting of the sleeves 136, 137 will shift the levers 134, 135 out of alinernent with the respective cams 146, 147 and 152, 153 and into alinement with the respective cams 144, 145 and 150, 151. As shown in FIGURES 3 and 4, the cams 150, 151 on the hub 141 are advanced approximately one-eighth of a revolution ahead of the cams 152, 153 and the cams 144, 145 on the hub 140 are advanced approximately one-eighth of a revolution ahead of the cams 146, 147. The purpose for positioning the cams in offset relationship and for shifting the two levers 134, 135 from one set of cams to another will be described in detail in the description of the operation of the machine in the knitting of a hose.

Method of operation In the knitting of ladies sheer non-run hosiery, it is the common practice to knit a turned welt at the top of the hose while forming plain stitches on all of the needles. Therefore, the sinker control cams 31 and 83 must be maintained in inactive or withdrawn position during the knitting of the welt so that the needles form plain stitch loops over the stitch drawings ledges 71 in front of the nebs 70, in the manner shown in FIGURE l2. In the present instance, the stitch control cams 81 and 83 are held in inoperative position by movement of the reading ends of the levers 120 and 121 up onto the respective cams 130 and 131 (FIGURES 6 and 7) to thereby pull on the corresponding Bowden wires 112, 113 and withdraw both the plungers 100 and 101 and allow the tension springs 84, 86 to move the respective sinker control cams 81, 83 to the inoperative position shown in FIGURES 8 and l2. With both of the sinker control cams 81, 83 held outwardly in an inoperative position, the butts of both the short and long butt sinkers S and S will engage the needle control cam 82 to be moved inwardly after the needles have been lowered and the yarn formed into stitch loops over the rst sinker drawing ledge 71 and in front of the nebs 70, as shown in FIGURE 12.

The turned welt is formed in the usual manner by use of the transfer points, not shown, which are supported in the dial of the knitting machine in the usual manner. Upon completion of the turned welt, it is customary to also knit an after-welt or shadow-welt of plain stitches in the same manner. Upon completion of the shadowwelt, the auxiliary pattern drum 125 will move with rotation of the main pattern drum 33 sothat the levers 120, 121 move off of the cams 130, 131 thereby releasing the corresponding Bowden wires 112, 113 and releasing the plungers 100, 101 to be controlled by the secondary control means, including the Bowden wires 1@ 104, 105 during the knitting of the non-run leg portion of the hose. It is also customary at the beginning of the knitting of the non-run leg portion of the hose to change yarns and feed a lightweight or light denier yarn to the needles.

When control of movement of the plungers 100, 101 is taken over by the secondary control means, these plungers 100, 101 are moved in and out to control the operation of the upper and lower sinker control cams 81, S3 by means of the cams on the hub portions 140, 141 of the control gear 142. Assuming that the rst course in the non-run leg is to be a plain course formed on all needles and formed of relatively short stitches, the levers 134, 135, will be in engagement with the respective cams 146, 152, as shown in FIGURES 3 and 4, respectively, so that the plungers 100 and 101, will be maintained in an outward position away from the sinker cap 55 so that the upper and lower sinker control cams 31, 83 remain in the inoperative position shown in FIG- URES 8 and 12. With the sinker control cams 81, 83 in this inoperative position, both the short and long butt sinkers S and S will remain in their outermost position until after the stitches have been formed by the needles N and the yarns will be drawn down over the stitch drawing ledges 71 in front of the nebs 70 to form small or short stitch loops on all the needles while the sinker control cams 81, 83 are inoperative. As soon as the stitches have been formed over these stitch drawing ledges 71, the butts of all the sinkers will engage the center sinker control cam 82 to be moved inwardly, as indicated in FIGURE 8 and the nebs 70 will thus shed the stitches which are cast from the needles N, in the usual manner.

As the needle cylinder rotates from the position shown in FIGURE 8 in a counterclockwise direction, the reading end of the lever 134 moves oil? of the cam 146 and into engagement with the hub portion 140 of the control gear 142 to thereby release the plunger 100 and allow the upper sinker control cam 81 to move inwardly to operative position while the group of short butt sinkers S are passing the knitting station. Since the upper control cam 81 moves inwardly to operative position while the group of short butt sinkers S are passing thereby, none of these short butt sinkers will be moved inwardly by the sinker control cam 81 because it it positioned above the tops of the butts of the short butt sinkers, as is clearly shown in FIGURE 12.

However, when the group of long butt sinkers S (FIG- URES 9 and 13) pass the knitting station, the upper sinker control cam 81 will move inwardly at a point in advance of the point at which the short butt sinkers S were moved in by the cam 82 to start the knitting of the second course. Thus, in this second course the sinkers are moved inwardly before the needlesv are lowered to stitch drawing level so that the yarn is drawn down over the high stitch drawing ledge 72 and behind the neb 70, as is shown in FIGURE 13, to form long or large stitch loops. Also, during this second course of the leg, the conventional needle selector means operates to raise alternate needles to shed level and to raise intervening needles to tuck level so that when the needles take the yarn and pass beneath the stitch cam, alternate needles will form long plain stitches and intervening needles will form long tuck stitches.

While this group of long butt sinkers S is passing through the knitting station, the reading end of the lever 135 moves off of the cam 152 and into engagement with the periphery of the hub of the gear 142 (FIGURE 4) to thereby release the lower plunger 101 so that the lower sinker control cam 83 will move inwardly to operative position after a portion of this second course has been knit. With both sinker control cams 81, 83 in operative position, as shown in FIGURES 10 and 14, the upper cam 81 continues to move the long butt sinkers inwardly earlier than normal and then the group of short butt sinkers S will be moved inwardly by the'lower sinkercontrol cam 83 to form long tuck and plain stitches and complete this second course of the leg.` During the knitting of thelast portion of this second course and `while the group of short butt sinkers S is passing-the knitting` station, the cam 147 (FIGURE 3)*moves into engagement with the reading end ofthe lever 134 to thereby withdraw the plunger 1% and. cause the spring $4 to move the upper sinker controlcam 81 to withdrawn ork inoperative position. Y

The lower sinker control cam V8 3 -will remain inwardly to continue to moveall of the short butt sinkers S inwardlybut the-long butt sinkers S will not be moved inwardly because the cut-outs 73therein will allow themto re-` main in an outer position until their butts arerengaged by.

draw the yarn down over the stitch drawing ledges 71 inY front of the nebs 79 of the sinkers. While the long butt 9 by movement of the reading end of the lever 134 olf of.

the cam-147 on the hub140 of the gear 142 (FIGURE 3). Then, the upper sinker control cam 81 will beY in op-v erative position to moverthe group of vlong butt sinkers S inwardly earlier than normal kand begin the knitting of the fourth course on the needle besidethe-iirst long butt sinker S'. by the sinker control cam S1 to beginknitting thefourthcourse, the conventional needle selector means-operates to raise alternate needles to tuck levelandito raise intervening'needles-to shed level so that when -the needles take the yarn and p ass beneath the stitch cam, alternate;

needles will draw'the yarn-down over the stitch-drawing ledges 72 to form long tuckV stitches while-intervening needles will draw they yarn-down overthe stitch drawingy ledges 72 to form longplain stitches- This is in contrast to the second course where alternateV needles formed long. plain stitches and intervening needlesformed long tuck stitches.

While the group of long butt sinkers S' is passing through the knitting station to form the leadingend` of this fourth course, the reading end of the-lever 135 moves olf of the cam 153 and into engagement with the periphery of the hub 149 of the gear Mii-(FIGURE 4) to thereby release the lowerplunger 1G1- so thatthe lower sinker control cam 83 will move inwardly to operative position. With both sinkercontrol Cams 81; S3 in operative position, as shown in FIGURES ltland 14. the group of [short butt sinkers S will be moved inwardlyhy the lower sinkcr control cam 83 to form long tuckandplain stitches and Complete this fourth course of the leg. During `the knitting of the Vlast portion ofl thisfourth course and while theY Ygroup of short butt sinkers- S is passing the knitting-station, thecam 146- (FIGURE 3) moves into engagement with the reading end of the lever-134 to thereby cause the upper sinker control cam 81 to move to withdrawn or inoperative position.-

The lower sinker control-cam S3 will remaininwardly to continue tomove all` of the short butt sinkers S inwardly to complete the knitting of this fourth course on the needlebesidev the last short butt sinker but the long butt sinkers S will not be moved inwardly because the cut-outs 73 therein will allora/.them to remain in anouter position until their butts are engagedby the center cam' During` As the longY buttsinkers S' are moved linwardly Y foot of the hose.

12 82 to` thus start the knitting ofthe fifth course on the needle beside the first long butt sinker S'.

Theknitting ofthe fifth, sixth, seventh and eighth courses is identical to the knitting of the respective first, second, third and fourth courses described above. It 1s to be notedthat the gear 142 makesone complete rotation with the knitting of each four courses and therefore the cycle described in connection with the vfirst four courses is repeated and the gear 142 makes a complete revolution with each four rotations of the needle cylinder-25t-hrough-` When the required number of courses have been knit. inthe leg of, the stocking, bothsinker control cams 8L 33 are maintained in inoperative position by. movement of thelever 1Z0 (FIGURE 6) up onto the heel cam 13.2.

and by movement of the lever 121 (FIGURE 7) up onto the heel cam 133. VWhile the sinker controlcams arev held in inoperative position, the heel pocket is knit in the usual manner, formingplain stitches by the needles drawingthe yarn-down over thevstitch. drawingledges 71 of theV sinkerswhilethe needle cylinder is reciprocated and the needles are widened and narrowed-to form the fashioned gussets of theV heel pocket inthe usual manner..

Upon completion of the heel pocket, it is the usual practice to disconnect the needle cylinderrfrom the drive mechanism to shog the needle cylinder one-half of a revolution relative to the drive mechanism so that it is possible` to later knit the toe pocketon the opposite-side of the cylinder andlthen the looperlinewill extend beneath the When this is done, the driving-mechanism of the knitting machine including-the gear 142, is advanced one-eivhthof a revolution ahead of the needle. cylinder, as comparedtothe-relationship of the drivingmechanism to the needle cylinder during the knitting of the leg. Therefore,Y it-is necessary at this point to change the timing of the operation of the sinker control cams 81, 83 to correspondwith the new relationship between the. needle cylinderfand-the drive mechanism.

This changing of the timing of the operation of; theV sinker control vcams 81, S3 is accomplished by movementof the lever 17@ (FIGURE 5 up onto the cam 172 to pull' on the Bowden wire 173 and shift the two levers 1345 135' to the left of the position shown in FIGURE 2-so-that their reading ends Vthen are in position in alinement withY the respective cams 144, 145 and 150, 151 yon the gear 142.` This shifting of the levers to the-adjacent-cam-rows insures that the alternating long and short stitch-loop courses will still be started and stopped at the same needle, preferably the needle whichforms the Wale extending down the middle of the back'of thelegand beneath-the bottom of the foot of the hose.-

Then during the knitting of the non-run fabric in the foot of-v the hose, the sinker control cams 81 and-85 still operate in the same manner as they operated duringthe knittingof the leg of the hose so-thatduring-alternate rotations of the needle cylinder` the sinkersv remain iny outermost position and the needles form shortplain stitch loops over the stitchdrawingledges 71 infront-0f the nebs 7tl`of all the sinkers, and fthen-during-intervenf ing rotations of the needle cylinder the sinkers-are moved in and the needlesform long tuck and plain stitch loops over the stitch drawing ledges 72 behind thenebs 741 of all the sinkers. However, during the knittingof the foot,` the cams 144,v 145 (FIGURE 3) and 150, 151i (FIG` URE 4) control movement of the respective levers 134 and 135 and operation of theicorresponding sinker control cams 81, 83.

As soon as the desired number of courseshave been knit to formV the non-runffoot'portionofthe hose,.the levers 120, 121 (FIGURES .6 and 7) move up onto the respective cams 139: 131 on the auxiliary pattern' drum to thus stop the inand outmotion of the sinkercontrol cams 81 and 83 and the machine again knits plain fabric in a few ring courses before knitting the toe pocket. With both sinker control cams 81 and 83 in inoperative position7 as shown in FIGURE 8, the sinkers S and S engage and are moved inwardly by the sinker control cam 82 so that the needles are drawn down to form regular plain stitch loops by drawing the yarn over the stitch drawing ledges 71 in front of the nebs 70. The toe pocket is then completed in the usual manner by reciprocatory motion of the needle cylinder 25 and the sinker withdrawing cam '76 (FIGUREl 8) acts to withdraw the sinkers as the yarn is fed to the needles as they alternately pass the knitting station in each direction. Then the sinkers are moved back inwardly to shed the stitch loops by the insert cam '7S in one direction and by the sinker control cam 82 as the needle cylinder moves in the opposite direction. With the completion of a hose, the drum 125 rotates and the lever 176i moves oi of the cam 172 (FIGURE 5) to shift the levers 134, 13S back to the position shown in FIGURE 2 before the knitting of the leg portion of the next hose.

In accordance with the sinker control means of the present invention the sinkers are maintained in an outermost position so that the needles form short stitch loops during every other rotation of the needle cylinder and then the sinkers are Vmaintained in an innermost position during the other rotations of the needle cylinder so that the needles form long stitch loops and this repeated operation is continued throughout the knitting of the non-run fabric in the leg and foot of a hose. The levers 120, 121 (FIGURES 6 and 7) and the corresponding cams carried by the auxiliary pattern drum 125 comprise a primary pattern control means which is used to :maintain the sinker control cams 81 and 83 in inoperative position during the knitting of portions of the hose, such as in the welt, shadow-welt, heel, ring toe courses, toe and loopers rounds. The levers 134, 135 (FIGURES 3 and 4) and the corresponding cams on the races on each of the hubs 140 and 141 of the timing gear 142 comprise a secondary pattern control means which is controlled by the primary control means and is operative during the knitting of the leg and foot portions of the hose to alternately position the sinkers where the needles form short stitch loops and then position the sinkers where the needles form long stitch loops. The cam lever 170 (FIGURE 5) and its corresponding cam comprise a shifting means which is operable to change the timed relationship of the operation of the sinker control cams 81 and 83 relative-to rotation of the drive mechanism of the knitting machine.

In the drawings and specification there has been setl forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive senseonly and not for purposes in limitation, the scope of the invention being dened in the claims.

We claim:

1. In a circular hosiery knitting machine having a circular series of needles mounted for vertical movement in a needle cylinder, drive means for imparting rotation to said needle cylinder, sinkers supported for radial movement between said needles and cooperating therewith to form stitch loops, each of said sinkers having a neb with a low stitch drawing ledge in front of said neb and a high stitch drawing ledge behind said neb, and a sinker cap having sinker cam means normally being operable upon said sinkers to position the same where said needles form short stitch loops over said low stitch drawing ledges, the combination therewith of (a) a pair of sinker control cams supported in said sinker cap and movable between operative and inoperative positions and when in operative position eing operable upon said sinkers to position the same where said needles form long stitch loops over said high stitch drawing ledges,

(b) primary pattern control means operatively connected to said movable sinker control cams and being operable to maintain said movable sinker control cams in said inoperative position during the knitting of certain selected portions of the hose, and

(c) secondary pattern control means operatively connected to said movable sinker control cams and being operable to change the position of said movable sinker control cams with each rotation of said needle cylinder and during the knitting of other selected portions of the hose.

2. In a circular hosiery knitting machine according to claim 1 wherein said drive means includes a high speed gear and said secondary pattern control means (c) includes 15 (l) a timing gear supported in driven engagement with said high speed gear,

(2) cam means carried by said timing gear, and

(3) a pair of levers being operable by said cam means and being operatively connected to said movable sinker control cams to control the movement of said movable sinker control cams in timed relationship to rotation of said timing gear andsaid drive means. 3. lIn a circular hosiery knitting machine according to claim 2 wherein said cam means (2) includes first and second cam races for each of said levers, and including shiftingmeans operatively connected to said levers and being operable to shift the same between the corresponding cam races to change the movement of said movable sinker control cams relative to rotation of said timing gear and said drive means.

4. In a circular hosiery knitting machine according to claim 3 wherein said rst and second cam races for one of said levers are fixed on one side' of said timing gear and said rst and second cam races for the other of said levers are xed on the other side of said timing gear.

5. In a circular hosiery knitting machine having a circular series of needles mounted for vertical movement in 40 a needle cylinder, drive means for imparting rotation to said needle cylinder, clutch means interposed between said drive means and said needle cylinder and being operable toat times change the driving relationship between said needle cylinder and said drive means, sinkers supported for radial movement between said needles and cooperating therewith to form stitched loops, each of said sinkers having a neb with a low stitch drawing ledge in lfront of said neb and a high stitch drawing ledge behind said neb, and a sinker cap having primary sinker control cam means normally being operable upon said sinkers to position the same where said needles form short stitch loops over said low stitch drawing ledges, the combination therewith of (a) a pair of sinker control cams supported in said sinker cap and movable between operative and inoperative positions and when in operative position being operable upon said sinkers to position the same where said needles form long stitch loops over said high stitch drawing ledges,

(b) primary pattern control means operatively connected to said movable sinker control cams and being operable to maintain said movable sinker conltrol cams in said inoperative position during the knitting of certain selected portions of the hose, and

(c) secondary pattern control means operatively connected to said movable sinker control cams and being operable by and in timed relation to said drive means to change the position of said movable sinker control cams with each rotation of said needle cylinder and during the knitting of other selected portions of the hose, said secondary pattern control means includ ing shifting means operable to change the operation of said movable sinker control cams relative to said drive means to correspond with a change in the driving relationship between said needle cylinder and said drive means.

6. In-a circular hosiery knitting'machine having a Ycircular series of needles mounteclfor vertical movement in a needle cylinder, sinkers supported for radial movement between said needlesY and cooperating therewith to form stitch 1oopseach` of' said :sinkers having a neb with a low stitch drawingrledge in front-or said neb and a high stitch-drawing ledge behind said neb,.a iirstl group of successive sinkers having short operating butts, a second group ofy successive sinkers having longV operating butts, and Va sinker cap havingsinkencamrmeans normally being operable upon the butts of both groups'of 'sinkers to position thesarne where said needles :form ,short stitch loops over said low stitch drawing ledges, the combination therewithY of (n) a pair of sinker control cams supported in saidA sinker cap andvmovable between vojgrerative` andinoperative positions and whenin operative position being koperable upon said sinkers to position the same where said needles formlong stitch loops over saidV high` stitchY drawing ledges,

(1) one of said movable sinker control cams being positioned above said sinker cam means and being engageable with the butts of said second group of sinkers, Y

(2) the other of said movable sinker control Vcams being positioned below said sinker camtneans and being engageable withthe butts of said first group ofsinkers, Y

(3) the sinkers of said second group having cutouts in alinement with said other movable sinker control cam to prevent engagement with said other movable sinker control carn,A

(b) primary pattern control means operatively connected to said movable Vsinker control cams and being operable to maintain said movable sinkerv control cams in said inoperative position during` the knitting of certain selectedportions ofthe hose, `and (c) secondary pattern control,l means operatively connected to said movable sinker control cams and being operable to change the position of said movable sinker controlwiti1 each rotation of said needle cylinder and during the knitting of other selected portions of the hose.

7. In a circular hosiery knitting machine havinga .circular series of needles mounted for vertical movement in aneedle cylinder, drive means .for imparting rotation to said needle cylinder, clutch means interposed between said drive means and said needle cylinder andv being operable to at times change the driving relationship between said needle cylinder and said drive means, sinkers sup.- ported for radial movement between` said needles and cooperating therewith tok form stitchtloops-each of said sinkers having a neb with a low stitch drawing ledge in front of said neb and a high stitch drawingledge behind said neb, a first group of successive sinkers havingshort operating butts, a second' group of successive sinkers having long operating butts, and a sinker cap-having sinker` cam means normally being operable upon thevbntts of both groups of sinkers to position the same where said needles forrnrshort stitch loops over said lon.7 stitch drawing` ledges, the combination therewith of (a) a pair of sinker control cams supported in said sinker cap and movable between operative and inoperative positions and when in operative position being operable upon said sinkers to position the same l5. where said needles form long stitch loops over Said high stitch drawingledges,

(l) one of said movable sinker control'cams being` positioned above said sinker cam means and being engageable'with the buttsof said second.

group of sinkers, (2) the other of said movable sinker control cams being positioned below. said sinker cam means` andbeing engageable with the butts of said first group of sinkers, (3) thesinkers of said secondgroup having cutouts in alinement withsaid other movable sinker control cam to prevent engagement with saidV other movable sinker control cam,

(b) primary pattern control means operatively connected to saidmovable sinkerl control cams and being operableto maintainV said movable sinker control cams in said inoperative position during the knitting of certain selected lportionsof the hose, and

(c) secondary pattern control means operatively connected to said movable sinker control cams and being operable by and in timed relation to said drive means to change the position of said movable sinker control with each rotation of-said needle cylinder and during the knitting of other selected portionsV of the hose, said secondary pattern control means including shifting means operable to change the operation of said `movable sinker control cams relative tosaid drive means torcorrespond withV a change in the driving relationship between said needle cylinder and'said drive means.

8. ,In a circular hosiery knitting machine having a rotatable needle cylinder, a circular series of needles supported for vertical movement in said-cylinder, a single knitting station, sinkcrs having a neb with a low stitch drawing ledge in front of said neb and a high stitch drawing ledge behind said neb, and said-sinkers being radially movable relative to said needles at said knitting station, the combination therewith of (a)k cam meansV at the knitting station operable during y alternate single rotations of said needle cylinder for moving the sinkers inwardly relative to the needles to position said low stitch drawing ledges in operable position relative to the needles, whereby when the needles draw the yarn, the same willpass over said low stitch drawing ledges in front of said nebs to form short stitches,

g (b) cam means at thel knitting station operable during intervening single lrotations of said needle cylinder for moving the sinkers inwardly relative to the needles to position said high stitch drawing ledges in operable position relative to the needles, whereby when the needles draw the yarn, the same will pass over said high stitch drawing ledges behind said nebs to form short stitches.

References Cited in the file of this patent UNITED STATES PATENTS' 

1. IN A CIRCULAR HOSIERY KNITTING MACHINE HAVING A CIRCULAR SERIES OF NEEDLES MOUNTED FOR VERTICAL MOVEMENT IN SAID NEEDLE CYLINDER, DRIVE MEANS FOR IMPARTING ROTATION TO SAID NEEDLE CYLINDER, SINKERS SUPPORTED FOR RADIAL MOVEMENT BETWEEN SAID NEEDLES AND COOPERATING THEREWITH TO FORM STITCH LOOPS, EACH OF SAID SINKERS HAVING A NEB WITH A LOW STITCH DRAWING LEDGE IN FRONT OF SAID NEB AND A HIGH STITCH DRAWING LEDGE BEHIND SAID NEB, AND A SINKER CAP HAVING SINKER CAM MEANS NORMALLY BEING OPERABLE UPON SAID SINKERS TO POSITION THE SAME WHERE SAID NEEDLES FORM SHORT STITCH OVER SAID LOW STITCH DRAWING LEDGES, THE COMBINATION THEREWITH OF (A) A PAIR OF SINKER CONTROL CAMS SUPPORTED IN SAID SINKER CAP AND MOVABLE BETWEEN OPERATIVE AND INOPERATIVE POSITIONS AND WHEN IN OPERATIVE POSITION BEING OPERABLE UPON SAID SINKERS TO POSITION THE SAME WHERE SAID NEEDLES FORM LONG STITCH LOOPS OVER SAID HIGH STITCH DRAWING LEDGES, 